The poll showed growing support for the other candidates. But only days before Tuesday's primary, U.S. Rep. Allyson Schwartz had 14 percent, state Treasurer Rob McCord had 9 percent and former state environmental protection chief Katie McGinty had 5 percent.

The telephone poll of 530 Democratic voters was conducted between May 6 and Monday. It carried a sampling error margin of plus or minus 4.3 percentage points.